Solving a problem in physics section 63 point 55 electr

55. The coil winding with iron core contains N = 500 turns. core length l = 50 cm. As the number of times to change the inductance L of the solenoid, if the current flowing through the coil rise from I1 = 0,1 A to I2 = 1 A? To solve the problem in the use of graph H shown in Fig.